Running for only a few minutes a day - even at slow speeds - may reduce a person's risk of death from heart disease and other causes compared to someone who does not run, according to a new 15-year study.

In the study, runners on average lived three years longer compared to non-runners, researchers said.

They studied 55,137 adults between the ages of 18 and 100 over a 15-year period to determine whether there is a relationship between running and longevity.

Data was drawn from the Aerobics Center Longitudinal Study in the US, where participants were asked to complete a questionnaire about their running habits.

In the study period, 3,413 participants died, including 1,217 whose deaths were related to cardiovascular disease. In this population, 24 per cent of the participants reported running as part of their leisure-time exercise.

Compared with non-runners, the runners had a 30 per cent lower risk of death from all causes and a 45 per cent lower risk of death from heart disease or stroke. Runners on average lived three years longer compared to non-runners.

The benefits were the same no matter how long, far, frequently or fast participants reported running. Benefits were also the same regardless of sex, age, body mass index, health conditions, smoking status or alcohol use.

The study showed that participants who ran less than 51 minutes, fewer than 9.6 km, slower than 9.6 km per hour, or only one to two times per week had a lower risk of dying compared to those who did not run.

D C Lee, lead author of the study and an assistant professor in the Iowa State University Kinesiology Department in Ames, Iowa, said they found that runners who ran less than an hour per week have the same mortality benefits compared to runners who ran more than three hours per week.

Thus, it is possible that the more may not be the better in relation to running and longevity, researchers said.

Researchers also looked at running behaviour patterns and found that those who persistently ran over a period of six years on average had the most significant benefits, with a 29 per cent lower risk of death for any reason and 50 per cent lower risk of death from heart disease or stroke.

"Running may be a better exercise option than more moderate intensity exercises for healthy but sedentary people since it produces similar, if not greater, mortality benefits in five to 10 minutes compared to the 15 to 20 minutes per day of moderate intensity activity that many find too time consuming," Lee said.

The study was published in the Journal of the American College of Cardiology.